212 AN INTRODUCTION TO ENTOMOLOGY 



TA BLE FOR DETERMINING THE ORDERS OF THE HEX A POD A 



This table is merely intended to aid the students in determining to which of 

 the orders a specimen that he is examining belongs. No effort has been made to 

 indicate in the table the relation of the orders to one another. 



A. Winged. (The wing-covers, Elytra, of beetles and of earwigs are wings.) 

 B. With two wings. 



C. Wings horny, leathery, or parchment-like. 



D. Mouth-parts formed for sucking. Wings leathery, shortened, or 



membranous at the tip. p. 350 Hemiptera 



DD. Mouth-parts formed for biting. Jaws distinct. 



E. Wings horny, without veins. Hind legs not fitted for jumping. 



p. 464 COLEOPTERA 



EE. Wings parchment-lilce with a network of veins. Hind legs fitted 



for jumping, p. 230 Orthoptera 



CC. Wings membranous. 

 . D. Abdomen with caudal filaments. Mouth-parts vestigial. 



E. Halteres wanting, p. 308 Ephemerida 



EE. Halteres present (males of Coccidas). p. 394 Homoptera 



DD. Abdomen without caudal filaments. Halteres in place of second 



wings. Mouth-parts formed for sucking, p. 773 Diptera 



BB. With four wings. 



C. The two pairs of wings unlike in structure. 



D. Fore wings reduced to slender club-shaped appendages; hind wings 

 fan-shaped with radiating veins. Minute insects, p. 546. .Strepsiptera 

 DD. Front wings leathery at base, and membranous at tip, often over- 

 lapping. Mouth-parts formed for sucking, p. 350. . .Hemiptera 

 DDD. Front wings of same texture throughout. 



E. Front wings horny or leathery, being veinless wing-covers. (Ely- 

 tra). 

 F. Abdomen with- caudal appendages in form of movable forceps. 



p. 460 Dermaptera 



FF. Abdomen without forceps-like appendages, p. 464. Coleoptera 



EE. Front wings leathery or parchment-like with a network of veins. 



F. Under wings not folded; mouth-parts formed for sucking. 



G. Beak arising from the front part of the head. p. 350. Hemiptera 



GG. Beak arising from the hind part of the lower side of the head. 



p. 394 Homoptera 



FF. Under wings folded lengthwise. Mouth-parts formed for 



chewing, p. 230 Orthoptera 



CC. The two pairs of wings similar, membranous. 



D. Last joint of tarsi bladder-like or hoof-like in form and without 



claws, p. 341 Thysanoptera 



DD. Last joint of tarsi not bladder-lilce. 



E. Wings entirely or for the greater part clothed with scales. Mouth- 

 parts formed for sucking, p. 571 Lepidoptera 



EE. Wings naked, transparent, or thinly clothed with hairs. 



F. Mouth-parts arising from the hinder part of the lower surface of 

 the head, and consisting of bristle-lil<;e organs inclosed in a jointed 



sheath, p. 394 Homoptera 



FF. Mouth-parts in normal position. Mandibles not bristle-like. 

 G. Wings net-veined, with many veins and cross-veins. 

 H. Tarsi consisting of less than five segments. 



I. Antennas inconspicuous, awl-shaped, short and slender. 

 J. First and second pairs of wings of nearly the same length; 



tarsi three-jointed, p. 314 Odonata 



JJ. Second pair of wings either small or wanting; tarsi 

 four-jointed, p. 308 Ephemerida 



II. Antenna usually conspicuous, setiform, filiform clavate, 

 capitate, or pectinate. 



J. Tarsi two- or three- jointed. 



K. Second pair of wings the smaller. Pc 33 1 . Corrodentia 



